Introduction

The medial malleolus osteotomy creates access to the medial compartment of the ankle joint. It provides a working area that covers the medial talus (from anterior to posterior) and the ankle joint itself.

Examples of surgical procedures that can be performed are:

- Treatment of osteochondral defects (e.g. by implanting a Hemicap/ocd OATS/Bonecraft

- Removal of large fragments and ossicels 

Anatomy

Prior to the curved incision over the medial malleolus, be aware of important anatomic structures, like the posterior tibial tendon, -artery and -vein. During the procedure, visualize the posterior tibial tendon and incise the sheet.

To identify the appropriate osteotomy plane, use an arthroscopic probe placed in the anterior and posterior medial corner of the tiial plfond. To visualize this plane, incize the periost. An anatomical reduction after the osteotomy is ensured by predrilling the screwholes which are used to fixate the osteotomy.

When performing the osteotomy, be aware of the talar cartilage. It is helpfull to use the arthroscopic probe, placed in the corners of the tibial plafond, for correct direction of the osteotomy and the apropriate depth
Diagnostic Imaging
For specific details on imaging in patients with large osteochondral defects, please see chapter 'Hemicap implantation'.

Depending on the patient' complaints, imaging can be performed to establish an accurate location of loose fragments and/or precise location of an osteochondral defect. If plain radiographs do not give adequate information, computed tomography can depict and localize bony fragments and location and size of a osteochondral defect.

Recommended literature

van Bergen CJ, Tuijthof GJ, Sierevelt IN, van Dijk CN. Direction of the oblique medial malleolar osteotomy for exposure of the talus. Arch Orthop Trauma Surg. 2011 Jul;131(7):893-901